Luke indicated that Jesus told the former demoniac to return to his home (Ὑπόστρεφε εἰς τὸν οἶκόν σου). There he was to declare how much God had done for him (καὶ διηγοῦ ὅσα σοι ἐποίησεν ὁ Θεός). Thus, he went away (καὶ ἀπῆλθεν), proclaiming throughout the whole city (καθ’ ὅλην τὴν πόλιν κηρύσσων) how much Jesus had done for him (ὅσα ἐποίησεν αὐτῷ ὁ Ἰησοῦς). There is something similar in Mark, chapter 5:19-20, while there is nothing like this in Matthew. Mark said that Jesus refused this former demoniac’s request. Jesus would not permit him to go with them. However, Jesus told him to go to his own home. There he was to preach, announce, or tell others how much the Lord (ὁ Κύριός) had done for him with his great mercy. This former demoniac went away. He then began to preach or proclaim in the Decapolis area how much Jesus had done for him. Thus, everyone there was amazed or marveled at this. The Decapolis territory was a group of 10 gentile non-Jewish cities on the east bank of the Jordan River in present day Jordan and Syria that included the towns of Gerasa, Scythopolis, Hippos, Gadara, Pella, Philadelphia, Capitolias, Canatha, Raphana, and Damascus. Thus, this cured demoniac was the first Christian apostle to the gentiles, a foreign missionary rather than a close disciple or apostle. Would you rather be a missionary for Jesus or one who followed him closely?

Matthew, chapter 15:29, has a more summary explanation of this travel. Instead of going to Sidon, Jesus went straight back to the Sea of Galilee. Also, there is no mention of Jesus going up a mountain here. Mark said that Jesus returned from the region of Tyre (Καὶ πάλιν ἐξελθὼν ἐκ τῶν ὁρίων Τύρου) by way of the coastal city of Sidon (ἦλθεν διὰ Σιδῶνος) that was further north. Then he went towards the Sea of Galilee (εἰς τὴν θάλασσαν τῆς Γαλιλαίας). However, he went through the middle of the Decapolis region (ἀνὰ μέσον τῶν ὁρίων Δεκαπόλεως), where he had been earlier in Mark, chapter 5:20. The Decapolis territory was a group of 10 gentile non-Jewish cities north and east of the Jordan River in present day Jordan and Syria that included the towns of Gerasa, Scythopolis, Hippos, Gadara, Pella, Philadelphia, Capitolias, Canatha, Raphana, and Damascus. Clearly, Jesus had gone through these gentile, non-Jewish areas.

There is something similar in Luke, chapter 8:39, while there is nothing like this in Matthew. Mark said that the former demoniac went away (καὶ ἀπῆλθεν). He then began to preach or proclaim (καὶ ἤρξατο κηρύσσειν) in the Decapolis area (ἐν τῇ Δεκαπόλει) how much Jesus had done for him (ὅσα ἐποίησεν αὐτῷ ὁ Ἰησοῦς). Thus, everyone there was amazed or marveled at this (καὶ πάντες ἐθαύμαζον). The Decapolis territory was a group of 10 gentile non-Jewish cities on the east bank of the Jordan River in present day Jordan and Syria that included the towns of Gerasa, Scythopolis, Hippos, Gadara, Pella, Philadelphia, Capitolias, Canatha, Raphana, and Damascus. Thus, this cured demoniac was the first Christian apostle to the gentiles.